Merge tag 'mvebu-fixes-4.14-1' of git://git.infradead.org/linux-mvebu into fixes
[linux-2.6-block.git] / arch / x86 / include / asm / thread_info.h
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1/* thread_info.h: low-level thread information
2 *
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
5 */
6
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7#ifndef _ASM_X86_THREAD_INFO_H
8#define _ASM_X86_THREAD_INFO_H
2052e8d4 9
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10#include <linux/compiler.h>
11#include <asm/page.h>
198d208d 12#include <asm/percpu.h>
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13#include <asm/types.h>
14
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15/*
16 * TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we
17 * reserve at the top of the kernel stack. We do it because of a nasty
18 * 32-bit corner case. On x86_32, the hardware stack frame is
19 * variable-length. Except for vm86 mode, struct pt_regs assumes a
20 * maximum-length frame. If we enter from CPL 0, the top 8 bytes of
21 * pt_regs don't actually exist. Ordinarily this doesn't matter, but it
22 * does in at least one case:
23 *
24 * If we take an NMI early enough in SYSENTER, then we can end up with
25 * pt_regs that extends above sp0. On the way out, in the espfix code,
26 * we can read the saved SS value, but that value will be above sp0.
27 * Without this offset, that can result in a page fault. (We are
28 * careful that, in this case, the value we read doesn't matter.)
29 *
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30 * In vm86 mode, the hardware frame is much longer still, so add 16
31 * bytes to make room for the real-mode segments.
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32 *
33 * x86_64 has a fixed-length stack frame.
34 */
35#ifdef CONFIG_X86_32
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36# ifdef CONFIG_VM86
37# define TOP_OF_KERNEL_STACK_PADDING 16
38# else
39# define TOP_OF_KERNEL_STACK_PADDING 8
40# endif
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41#else
42# define TOP_OF_KERNEL_STACK_PADDING 0
43#endif
44
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45/*
46 * low level task data that entry.S needs immediate access to
47 * - this struct should fit entirely inside of one cache line
48 * - this struct shares the supervisor stack pages
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49 */
50#ifndef __ASSEMBLY__
006c484b 51struct task_struct;
cd4d09ec 52#include <asm/cpufeature.h>
60063497 53#include <linux/atomic.h>
2052e8d4 54
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55struct thread_info {
56 unsigned long flags; /* low level flags */
57};
58
59#define INIT_THREAD_INFO(tsk) \
60{ \
61 .flags = 0, \
62}
63
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64#define init_stack (init_thread_union.stack)
65
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66#else /* !__ASSEMBLY__ */
67
68#include <asm/asm-offsets.h>
69
70#endif
71
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72/*
73 * thread information flags
74 * - these are process state flags that various assembly files
75 * may need to access
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76 */
77#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
59e52130 78#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
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79#define TIF_SIGPENDING 2 /* signal pending */
80#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
81#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
e57549b0 82#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
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83#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
84#define TIF_SECCOMP 8 /* secure computing */
7c68af6e 85#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
0326f5a9 86#define TIF_UPROBE 12 /* breakpointed or singlestepping */
afb94c9e 87#define TIF_PATCH_PENDING 13 /* pending live patching update */
e9ea1e7f 88#define TIF_NOCPUID 15 /* CPUID is not accessible in userland */
e57549b0 89#define TIF_NOTSC 16 /* TSC is not accessible in userland */
6bd33008 90#define TIF_IA32 17 /* IA32 compatibility process */
bf5a3c13 91#define TIF_NOHZ 19 /* in adaptive nohz mode */
0ddc9324 92#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
f80c5b39 93#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
e57549b0 94#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
e57549b0 95#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
ea8e61b7 96#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
b407fc57 97#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
66700001 98#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
6bd33008 99#define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
bb212724 100#define TIF_X32 30 /* 32-bit native x86-64 binary */
5ea0727b 101#define TIF_FSCHECK 31 /* Check FS is USER_DS on return */
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102
103#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
59e52130 104#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
e57549b0 105#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
e57549b0 106#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
3a404842 107#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
e57549b0 108#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
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109#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
110#define _TIF_SECCOMP (1 << TIF_SECCOMP)
7c68af6e 111#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
0326f5a9 112#define _TIF_UPROBE (1 << TIF_UPROBE)
afb94c9e 113#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING)
e9ea1e7f 114#define _TIF_NOCPUID (1 << TIF_NOCPUID)
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115#define _TIF_NOTSC (1 << TIF_NOTSC)
116#define _TIF_IA32 (1 << TIF_IA32)
bf5a3c13 117#define _TIF_NOHZ (1 << TIF_NOHZ)
f80c5b39 118#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
e57549b0 119#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
e57549b0 120#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
ea8e61b7 121#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
b407fc57 122#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
66700001 123#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
6bd33008 124#define _TIF_ADDR32 (1 << TIF_ADDR32)
bb212724 125#define _TIF_X32 (1 << TIF_X32)
5ea0727b 126#define _TIF_FSCHECK (1 << TIF_FSCHECK)
e57549b0 127
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128/*
129 * work to do in syscall_trace_enter(). Also includes TIF_NOHZ for
130 * enter_from_user_mode()
131 */
d4d67150 132#define _TIF_WORK_SYSCALL_ENTRY \
66700001 133 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
392a6254 134 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
bf5a3c13 135 _TIF_NOHZ)
d4d67150 136
00c1bb13 137/* work to do on any return to user space */
66700001 138#define _TIF_ALLWORK_MASK \
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139 (_TIF_SYSCALL_TRACE | _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
140 _TIF_NEED_RESCHED | _TIF_SINGLESTEP | _TIF_SYSCALL_EMU | \
141 _TIF_SYSCALL_AUDIT | _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE | \
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142 _TIF_PATCH_PENDING | _TIF_NOHZ | _TIF_SYSCALL_TRACEPOINT | \
143 _TIF_FSCHECK)
00c1bb13 144
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145/* flags to check in __switch_to() */
146#define _TIF_WORK_CTXSW \
e9ea1e7f 147 (_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP)
00c1bb13 148
7c68af6e 149#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
37f07655 150#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
00c1bb13 151
198d208d 152#define STACK_WARN (THREAD_SIZE/8)
b84200b3 153
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154/*
155 * macros/functions for gaining access to the thread information structure
156 *
157 * preempt_count needs to be 1 initially, until the scheduler is functional.
158 */
159#ifndef __ASSEMBLY__
160
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161/*
162 * Walks up the stack frames to make sure that the specified object is
163 * entirely contained by a single stack frame.
164 *
165 * Returns:
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166 * GOOD_FRAME if within a frame
167 * BAD_STACK if placed across a frame boundary (or outside stack)
168 * NOT_STACK unable to determine (no frame pointers, etc)
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169 */
170static inline int arch_within_stack_frames(const void * const stack,
171 const void * const stackend,
172 const void *obj, unsigned long len)
173{
174#if defined(CONFIG_FRAME_POINTER)
175 const void *frame = NULL;
176 const void *oldframe;
177
178 oldframe = __builtin_frame_address(1);
179 if (oldframe)
180 frame = __builtin_frame_address(2);
181 /*
182 * low ----------------------------------------------> high
183 * [saved bp][saved ip][args][local vars][saved bp][saved ip]
184 * ^----------------^
185 * allow copies only within here
186 */
187 while (stack <= frame && frame < stackend) {
188 /*
189 * If obj + len extends past the last frame, this
190 * check won't pass and the next frame will be 0,
191 * causing us to bail out and correctly report
192 * the copy as invalid.
193 */
194 if (obj + len <= frame)
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195 return obj >= oldframe + 2 * sizeof(void *) ?
196 GOOD_FRAME : BAD_STACK;
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197 oldframe = frame;
198 frame = *(const void * const *)frame;
199 }
96dc4f9f 200 return BAD_STACK;
0f60a8ef 201#else
96dc4f9f 202 return NOT_STACK;
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203#endif
204}
205
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206#else /* !__ASSEMBLY__ */
207
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208#ifdef CONFIG_X86_64
209# define cpu_current_top_of_stack (cpu_tss + TSS_sp0)
210#endif
211
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212#endif
213
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214#ifdef CONFIG_COMPAT
215#define TS_I386_REGS_POKED 0x0004 /* regs poked by 32-bit ptracer */
216#endif
8a6c160a 217#ifndef __ASSEMBLY__
ef334a20 218
ef334a20 219#ifdef CONFIG_X86_32
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220#define in_ia32_syscall() true
221#else
222#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
223 current->thread.status & TS_COMPAT)
ef334a20 224#endif
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225
226/*
227 * Force syscall return via IRET by making it look as if there was
228 * some work pending. IRET is our most capable (but slowest) syscall
229 * return path, which is able to restore modified SS, CS and certain
230 * EFLAGS values that other (fast) syscall return instructions
231 * are not able to restore properly.
232 */
233#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
234
61c4628b 235extern void arch_task_cache_init(void);
61c4628b 236extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
38e7c572 237extern void arch_release_task_struct(struct task_struct *tsk);
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238extern void arch_setup_new_exec(void);
239#define arch_setup_new_exec arch_setup_new_exec
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240#endif /* !__ASSEMBLY__ */
241
1965aae3 242#endif /* _ASM_X86_THREAD_INFO_H */